Safe and efficient collection of cell and fluid samples from a woman's genital tract is crucial to early and accurate diagnosis of many diseases. The Papanicolaou Test (widely known as the "Pap Test") is, for example, commonly performed on women in order to test for cervical cancer. According to the Pap Test, cell samples are smeared onto a glass slide and are then examined after staining. The diagnosis of many other diseases also depends on efficient collection of cell and fluid samples from the cervical area.
There are accordingly several known devices for collecting cellular material from the vaginal tract. The U.K. Patent No. 1,455,107 (Denson, Nov. 10, 1976), for example, describes a diagnostic tampon for collecting samples from the female genital tract. The Denson tampon comprises a semi-rigid cylindrical supporting body that is at least partially covered with a removable film; in one embodiment, the film is porous. When the Denson tampon is used for a Pap Test, it is inserted into the vagina to the point of contact with the cervix. Cells in the cervical area attach themselves to the film jacket of the tampon. After only a matter of minutes, the tampon is removed and the cells collected on the film are smeared onto slides and stained as in the conventional Pap Test.
The greatest drawback of the Denson tampon is the very fact that it is a tampon. Not only would it be very uncomfortable to leave a tampon-like cell collector in the vaginal cavity of a patient for long periods, but it also increases the risk that the patient will suffer from toxic shock. Consequently, a tampon device is ill-suited for collecting cell and fluid samples over periods longer than a few minutes or hours. It would be preferable to be able to leave a cell collector in the vaginal cavity for a long as twenty-four hours in order to obtain cell and fluid samples over an entire daily cycle of the patient's body.
U.S. Pat. No. 2,847,000 (Nieburgs, Aug. 12, 1958), describes yet another diagnostic tampon. In the Nieburgs device, a tampon is secured to a plunger within a cardboard tube. The tube is inserted into the vaginal cavity of the patient and the tampon is then pushed by the plunger so that it extends outside of the tube and absorbs samples from the cervical area. Thereafter, the tampon is retracted within the tube and passes over a slide that is mounted inside the tube. The tube, in which the slide has been smeared with fluids and cells collected by the tampon, may then be placed in an ordinary mailing container and shipped to a laboratory for examination. Like other tampon devices, the Nieburgs collector is not designed for collecting cell samples over a periods longer than a few minutes. The size and operation of the Nieburgs device also increase the discomfort of the patient.
U.S. Pat. No. 4,628,941 (Kosasky, Dec. 16, 1986) describes a cervical mucus collector that uses an arrangement in which a plunger pushes a collecting tip within a tube against the cervix. The Kosasky device is intended primarily for the patient to use on herself. A cup is attached to the inner end of the insertion tube in order to guide the tip of the plunger against the cervix, and the cup has a slitted cover that prevents contact by the plunger tip with unwanted vaginal fluids.
Like other cervical sample collectors, the Kosasky device is neither designed nor suited for collecting samples over more than short periods. The information gained from the cells and fluids collected during short sample times is naturally less than if one were able to collect samples over a period of a full day or more. Furthermore, the tubes and plungers used in devices such as are described in the Denson, Nieburgs, and Kosasky patents all constitute additional medical waste that must be disposed of.
An additional disadvantage of existing cervical cell collectors is that it is necessary or at least preferable to produce smears very soon after the devices are used in the patient, since there is no way to keep the cells moist and viable during collection. Therefore, not only can existing devices not be left in the vaginal cavity long enough to collect cell samples during an entire daily cycle, but also the cells that they do collect can often dry out and provide much less diagnostic information than they could if they could be kept moist up until the time of examination.
It is accordingly an object of this invention to provide a device for collecting cells and fluids from the cervical area that is small enough, comfortable enough, yet efficient enough to obtain samples at least over a full 24-hour period with a much lower risk of irritation or shock caused by the presence of a foreign object in the vaginal cavity.
It is a further object of the invention to provide a cervical cell collector that keeps collected cells moist until the device is removed from the patient and can be examined quickly using conventional methods.